Electric traction vehicle equipped with an air conditioning system operable even during parking and corresponding control method

Abstract

The electric vehicle (1) comprises: a chassis (2) supporting a pair of front wheels (3) and a pair of rear wheels (4); a passenger compartment (5) disposed between the front wheels (3) and the rear wheels (4); at least one electric motor (10) connected to the drive wheels (4); an electric energy storage device (13); an air conditioning system (16) designed to condition the passenger compartment (5) by heating or cooling air present in the passenger compartment (5); and a control unit (20) configured to operate the air conditioning system (16) even when the vehicle (1) is parked and connected to an external charging system (14), wherein the air conditioning system (16) has at least one thermal device (19) designed to directly exchange heat only with the chassis (2), and the control unit (20) is configured to operate the thermal device (19) only when the vehicle (1) is parked and connected to the external charging system.

Description

Technical Field

[0001] The present invention relates to an electric vehicle equipped with an air conditioning system that can also operate during parking and a corresponding control method.

[0002] [Cross - reference to related applications] This patent application claims priority from Italian Patent Application No. 102020000011677 filed on May 20, 2020, the entire disclosure of which is incorporated herein by reference.

[0003] The present invention finds an advantageous application in electric vehicles. Electric vehicles are explicitly referred to in the following description without loss of this generality.

Background Art

[0004] The main problem affecting current electric vehicles is range. This is because the amount of energy that an automotive battery can store is relatively limited and the charging time is very long (compared to the fuel refilling time of gasoline or diesel for vehicles equipped with internal combustion engines). Furthermore, since the temperature outside the vehicle is particularly harsh (i.e., very cold or very hot), when using the air - conditioning system to heat or cool the passenger compartment during driving, the relatively short range of the electric vehicle may be further reduced. Additionally, during the coldest times of the year, in a warm vehicle (i.e., a vehicle equipped with an internal combustion engine), the heat generated by combustion, which constitutes an energy loss for powering the vehicle, can be used "for free" to warm the passenger compartment, but this does not apply to electric vehicles. This is because the power train is very efficient, and the waste heat generated by the electric motor cannot be (easily) utilized by the electronic power converter and the electrical energy storage device.

[0005] During driving (especially along the first few kilometers of the route), in order to reduce the use of the air conditioning system and thus the electrical energy consumed by the air conditioning system, the manufacturer proposes to use the air conditioning system shortly before the start of driving (directly) when the electric vehicle is still connected to the charging system. In this way, instead of using the electrical energy stored in the battery of the electric vehicle, by using the electrical energy provided by the network, the passenger compartment can be brought to the desired temperature. During driving, the air conditioning system is used only for the purpose of maintaining the already existing desired temperature, and there is no need to use it to bring the passenger compartment from the ambient temperature to the desired temperature (there can be a temperature difference of several tens of degrees Celsius in mid-winter or mid-summer), so the amount of electrical energy saved is considerable (especially when the outside air temperature is particularly severe).

[0006] Basically, when the electric vehicle is parked and connected to the charging system, the driver sets the start time of driving, and thus the air conditioning system is automatically activated appropriately in advance (using the electrical energy provided by the charging system) so that the passenger compartment can reach the desired temperature at the exact start time of driving.

[0007] However, when the outside air temperature is particularly severe (i.e., very cold or very hot), as soon as driving starts, the passenger compartment tends to exchange a relatively large amount of heat with the outside, so the air conditioning system consumes a considerable amount of energy almost immediately.

[0008] German Patent Application No. 102010043335 and German Patent Application No. 102018004839 disclose electric vehicles in which the passenger compartment air conditioning system operates when the vehicle is parked and connected to an external energy source, so that when the driver gets into the vehicle and starts driving, the passenger compartment is already at the desired temperature.

[0009] German Patent No. 494879 describes an induction heating device for the chassis of an automobile.

[0010] Japanese Patent Publication No. JP-A-11-42924 discloses an automobile in which a door sill (i.e., the chassis portion under the door) is hollow inside and is used as a pneumatic channel for supplying conditioned air (either hot or cold) generated by an air conditioning system located at the front position toward the rear door. As a result, the conditioned air can be diffused through the rear door within the area of the rear seat.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] An object of the present invention is to provide an electric vehicle equipped with an air conditioning system that can operate even when parked and a related control method, which is not affected by the above-mentioned drawbacks and is at the same time manufactured easily and economically.

MEANS FOR SOLVING THE PROBLEMS

[0012] According to the present invention, there is provided an electric vehicle equipped with an air conditioning system that can operate even when parked and a related control method according to the appended claims.

[0013] The appended claims describe preferred embodiments of the present invention and form an integral part of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]

Figure 1

Figure 2

Figure 3

MODE FOR CARRYING OUT THE INVENTION

[0015] Here, the present invention will be described with reference to the accompanying drawings, which show non-limiting embodiments thereof. In FIG. 1, reference numeral 1 indicates an automobile having a rear (or central) motor, generally including a chassis 2 (schematically shown in FIGS. 2 and 3) that indicates a pair of front wheels 3 and a pair of rear wheels 4 as a whole.

[0016] There is a passenger compartment 5 that is accessible via a pair of doors 6 between the front wheels 3 and the rear wheels 4. At the front, the passenger compartment 5 is separated by a windshield 7. In front of the passenger compartment 5, there is a front compartment 8 (for example, but not limited to, luggage) whose upper part is closed by a front-hinged hood 9. Behind the passenger compartment 5, there is a rear motor compartment, whose upper part is closed by a rear-hinged hood.

[0017] According to FIG. 3, the automobile 1 has an electric drive unit (power train) and includes two electric motors 10, each of which is connected to a corresponding rear drive wheel 3 by a mechanical drive system 11 (including, for example, a planetary gear device). Each electric motor 10 is controlled by a corresponding electronic power converter 12 that provides an AC voltage to the corresponding stator winding and exchanges electrical energy with a storage device 13. According to FIG. 1, when the automobile 1 is parked, the automobile 1 can be connected to an external charging system 14 that supplies electrical energy to the storage device 13 via a cable.

[0018] According to FIGS. 2 and 3, the chassis 2 includes a set of internally hollow boxed elements 15. The boxed elements 15 are made of, for example, a light metal alloy (generally speaking, an aluminum-based alloy), manufactured by extrusion, and preferably consist of internally hollow linear bars joined to each other by welding in the region of structural nodes defined by joining the bodies.

[0019] According to FIG. 3, the motor vehicle 1 comprises a climate control system 16 designed to condition the passenger compartment 5 by heating or cooling the air present in the passenger compartment 5. In particular, the climate control system 16 comprises one or more fans 17 operated by respective electric motors and designed to generate forced air circulation, and an air treatment unit 18 designed to cool or heat the air circulated by the fans 17. Typically, the air treatment unit 18 comprises a heat pump operated by an electric motor. Furthermore, the climate control system 16 comprises a heat device 19 designed to exchange heat directly only with the chassis 2. That is, since the heat device 19 is completely dedicated to the operation only by the chassis 2, it cannot exchange heat with the passenger compartment 5.

[0020] Finally, the motor vehicle 1 comprises a control unit 20 configured to operate the climate control system 16 even when the vehicle 1 is parked and connected to an external charging system 14 (so as not to use the electrical energy stored in the storage device 13). In particular, when the vehicle 1 is parked and connected to the external charging system 14, the control unit 20 operates the climate control system 16 to condition the passenger compartment 5 and, using the heat device 19, heat the chassis 2 (if the climate control requires heating of the passenger compartment 5) or cool the chassis 2 (if the climate control requires cooling of the passenger compartment 5).

[0021] According to FIG. 3, the heat device 19 comprises a supply member 21 configured to supply at least a portion of the air treated by the treatment unit 18 to the chassis 2. That is, by means of the supply member 21, at least a portion of the air treated by the air treatment unit 18 is supplied to the chassis 2 instead of reaching the passenger compartment 5. In particular, the chassis 2 comprises at least one inlet opening 22 through which the air treated by the air treatment unit 18 enters the chassis 2 and at least one outlet opening 23 through which the air exits the chassis 2.

[0022] The processing unit 18 is configured to completely recirculate the air flowing out of the chassis 2 from the outlet opening 23. That is, in order to heat or cool the chassis 2, the same air is used without (as much as possible) using external air. In particular, the inlet opening 22 and the outlet opening 23 are close to each other on the same side of the chassis 2, and as a result, the air coming from the outlet opening 23 can be adjusted again and then reintroduced into the inlet opening 22, covering a relatively short path (that is, making the recirculation of air easier and more efficient).

[0023] The first path for the circulation of air processed by the air conditioning system 16 and intended for the air conditioning of the passenger compartment 5 is completely isolated from the second path for the circulation of air processed by the air conditioning system 16 and intended for the heating or cooling of the chassis 2. As a result, the air circulating in the passenger compartment 2 never mixes with the air circulating in the chassis 2. That is, the air processed by the air conditioning system 16 and intended for the air conditioning of the passenger compartment 5 is always separated from the air processed by the air conditioning system 16 and intended for the heating or cooling of the chassis 2. As a result, the two air paths share only a heat source or a cold heat source (consisting of a single common heat or cold heat generator of the air conditioning system 16) and do not share the same air. As a result, the air circulating in the passenger compartment 5 is isolated from the air circulating in the chassis 2.

[0024] According to a preferred embodiment, the chassis 2 includes at least one partition wall 24 inside, which separates the inlet opening 22 from the outlet opening 23 and creates a longer essential path that varies as much as possible between the inlet opening 22 and the outlet opening 23 inside the chassis 2 (in this way, the air supplied to the chassis 2 reaches the frame 2 as much as possible before reaching the outlet opening 23 by flowing through the inlet opening 22).

[0025] According to a possible simpler embodiment, the air treatment unit 18 is configured to introduce air at the same temperature into the passenger compartment 5 and the chassis 2. As a result, the air treatment unit 18 performs the same heat exchange on both the air introduced into the passenger compartment 5 and the air introduced into the chassis 2. According to an alternative more complex embodiment, the air treatment unit 18 is configured to introduce air at a lower temperature into the passenger compartment 5 compared to the air introduced into the chassis 2 when the air conditioning involves heating, and air at a higher temperature when the air conditioning involves cooling, and as a result, the air treatment unit 18 performs different heat treatments on the air introduced into the passenger compartment 5 and the air introduced into the chassis 2. This embodiment is more complex in that it requires differentiated air treatment within the air treatment unit 18, but provides the advantage of significantly cooling or heating the chassis 2 more than the passenger compartment 5 is cooled or heated so that the chassis 2 stores a large amount of heat or cold. In this regard, it should be noted that the temperature of the passenger compartment 5 needs to be about 18 - 20 °C in winter and about 26 - 28 °C in summer, but the chassis 2 can easily reach temperatures ranging from 10 °C (even in summer) to +60 °C (even in winter).

[0026] According to another embodiment, the heating device 19 can comprise at least one electric heater 25 (as an alternative to, or in addition to, the air treatment unit 18), which is attached to the chassis 2 so as to heat the chassis 2 by conduction. Typically, the electric heater 25 includes a resistor that generates heat by the Joule effect when an electric current flows through it.

[0027] According to a preferred embodiment, a heat insulation material 26 (schematically shown in Figure 2) is provided, which is arranged between the chassis 2 and the outside (in particular, but not limited to, between the chassis 2 and the road surface), and is not placed between the chassis 2 and the passenger compartment 5. The function of the heat insulation material 26 is to promote heat exchange between the chassis 2 and the passenger compartment 5, but reduce heat exchange between the chassis 2 and the outside.

[0028] In the embodiment shown in the attached drawings, the present invention is applied to an automobile 1, but the present invention can clearly be applied to different types of vehicles having a closed passenger compartment (e.g., vans, trucks, buses, etc.).

[0029] For this reason, the embodiments described herein can be combined with each other without exceeding the scope of protection of the present invention.

[0030] The above-mentioned automobile 1 has many advantages.

[0031] First, when the automobile 1 is used after being adjusted using the electrical energy provided by the charging system 14 at the previous parking stage, the passenger compartment 5 is not surrounded by the chassis 2 having the external temperature, and (initially) the chassis 2 having the same temperature as the passenger compartment 5 or a lower temperature than the passenger compartment 5 (when the air conditioning involves cooling) or a higher temperature than the passenger compartment 5 (when the air conditioning involves heating). Due to this fact, the passenger compartment 5 can maintain the desired temperature much longer even without the air conditioning system 16 operating.

[0032] This result is obtained by the fact that a substantial part of the mass of the automobile 1 (i.e., the chassis 2 and also the components that exchange heat with the chassis 2 through conduction) is used as a heat storage element to store thermal energy (high temperature in winter, low temperature in summer). Since an electric vehicle has a substantial mass, by making most of the mass of the vehicle high temperature in winter and low temperature in summer, during the first driving stage, it is not necessary to use a substantial part of the air conditioning system 16 that necessarily has to use the electrical energy stored in the storage device 13 for operation (thus reducing the distance range of the vehicle). This thermal energy can be used by the passenger compartment 5 to maintain an ideal temperature.

Explanation of Reference Numerals

[0033] 1 Automobile 2 Chassis 3 Front Wheel 4 Rear Wheel 5 Passenger Compartment 6 Door 7 Windshield 8 Front section 9 Front hood 10 Electric motor 11 Mechanical drive system 12 Electronic power converter 13 Storage device 14 Charging system 15 Boxed element 16 Air conditioning system 17 Fan 18 Air handling unit 19 Thermal device 20 Control unit 21 Supply member 22 Inlet opening 23 Outlet opening 24 Partition wall 25 Electric heater 26 Heat insulation material

Claims

1. An electric vehicle (1), comprising: a chassis (2) that supports a pair of front wheels (3) and a pair of rear wheels (4) and has a plurality of hollow box-shaped elements (15); a passenger compartment (5) disposed between the front wheels (3) and the rear wheels (4); at least one electric motor (10) connected to a drive wheel (4); an electrical energy storage device (13); an air conditioning system (16) designed to air-condition the passenger compartment (5) by heating or cooling the air present in the passenger compartment (5), and having an air treatment unit (18) designed to cool or heat the air; a control unit (20) configured to operate the air conditioning system (16) even when the vehicle (1) is parked and connected to an external charging system (14); wherein the vehicle (1) further comprises: the air conditioning system (16) has at least one heat device (19) suitable for directly exchanging heat only with the chassis (2) by supplying at least a part of the air treated by the air treatment unit (18) in the chassis (2); the chassis (2) has at least one inlet opening (22) through which the air treated by the air treatment unit (18) enters the chassis (2) and at least one outlet opening (23) through which the air exits the chassis (2); the control unit (20) is configured to operate the heat device (19) that supplies at least a part of the air treated by the air treatment unit (18) in the chassis (2) only when the vehicle (1) is parked and connected to the external charging system (14). An electric vehicle (1) characterized by the above.

2. The electric vehicle (1) according to claim 1, wherein the air treatment unit (18) is configured to recirculate the air exiting the chassis (2).

3. The electric vehicle (1) according to claim 1 or 2, wherein the inlet opening (22) and the outlet opening (23) are arranged on the same side of the chassis (2) such that the air coming from the outlet opening (23) can be adjusted again and then reintroduced into the inlet opening (22).

4. The first path through which the air, which is processed by the air conditioning system (16) and is intended for air conditioning of the passenger compartment (5), circulates is completely isolated from the second path through which the air, which is processed by the air conditioning system (16) and is intended for heating or cooling of the chassis (2), circulates. As a result, the air circulating through the passenger compartment (2) never mixes with the air circulating through the chassis (2). The electric vehicle (1) according to claim 1, 2 or 3.

5. The chassis (2) internally comprises at least one partition wall (24) separating the inlet opening (22) from the outlet opening (23) so as to create a longer essential path between the inlet opening (22) and the outlet opening (23) within the chassis (2). The electric vehicle (1) according to claim 3 or 4.

6. The air treatment unit (18) is configured to introduce air of the same temperature into the passenger compartment (5) and the chassis (2). The electric vehicle (1) according to any one of claims 2 to 5.

7. Compared with the air introduced into the chassis (2), the air treatment unit (18) is configured to introduce cooler air into the passenger compartment (5) when the air conditioning provides heating and warmer air when the air conditioning provides cooling. The electric vehicle (1) according to any one of claims 2 to 5.

8. The heating device (19) comprises at least one electric heater (25) attached to the chassis (2) for heating the chassis by heat conduction (2). The electric vehicle (1) according to any one of claims 1 to 7.

9. It comprises a heat insulating material (26) disposed between the chassis (2) and the external environment and not disposed between the chassis (2) and the passenger compartment (5). The electric vehicle (1) according to any one of claims 1 to 8.

10. The heat insulating material (26) is disposed at least between the chassis (2) and the road surface. The electric vehicle (1) according to claim 9.

11. A control method for an electric vehicle (1) according to any one of claims 1 to 10, comprising the step of operating the air conditioning system (16) to heat or cool the air present in the passenger compartment (5) to air-condition the passenger compartment (5) and to heat or cool the chassis (2), only when the vehicle (1) is parked and connected to an external charging system (14).

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